Given data:
Suppose two sides of the right angle triangle are a=3 meter and b=4 meter and in order to calculate the longest side, the expression for the Pythagoras theorem is,
![a^2+b^2=c^2](https://img.qammunity.org/2023/formulas/mathematics/high-school/fdnnfwrccw5g60jmi691r5gcz9ekxf8waa.png)
Substitute 3 meter for a, and 4 meter for b in the above expression.
![\begin{gathered} (3m)^2+(4m)^2=c^2 \\ 25m^2=c^2 \\ c=5\text{ m} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/6tndmgk61xejf7ru4hdalgmgvb4p6tbo7e.png)
Here, consider only positive value of c because length can't be negative.
Thus, the Pythagoras theorem is used to find the missing side of the right angle triangle when any two sides are given.